Type C Tanks and Pressurised LNG Transport Solutions

What it is

• Type C tanks are self-supporting pressure vessels commonly used in smaller LNG transport and bunkering applications. Their suitability depends on vessel size, cargo volume, operating profile, terminal infrastructure and project-specific design requirements.
• Because the tank is designed as a pressure vessel, vapour generated during a voyage can be accommodated by a designed pressure rise rather than continuous vapour handling — how far that holding capability extends is entirely project-specific.

Where it is used

• Small-scale LNG carriers, feeder vessels, coastal and inland barges, and dedicated LNG bunkering vessels.
• LNG fuel tanks on gas-fuelled ships across many vessel segments.

Key design characteristics

• Cylindrical or bi-lobe geometry chosen to suit hull form and required volume.
• Design pressure, insulation arrangement and relief systems set per project.
• Self-supporting structure that does not rely on the hull for cargo load transfer.

Benefits

• Vapour handling can be simplified in services with short voyages and frequent port calls.
• Construction and survey practice draws on established pressure-vessel engineering.

Operational considerations

• Curved pressure-vessel geometry generally uses hull volume differently from hull-conforming membrane tanks.
• No single set of pressure, capacity or boil-off figures applies to all Type C installations.
• Type C is not universally better or worse than membrane containment: suitability follows the application.

Related vessel segments

• Small-scale
• Bunkering
• Feeder
• LNG barge
• LNG-fuelled vessel

Related glossary terms

• Type C Tank
• Pressure Vessel
• Bi-Lobe Tank
• LNG Bunkering
• Boil-off Gas